1. Field of the Invention
The present invention relates generally to a state-of-device remote monitor system, and more particularly to a state-of-device remote monitor system for remotely obtaining various categories of data about a temperature, vibrations and so on in an operating state of an electric device such as an electric motor.
2. Description of the Related Art
In a large-scale plant such as a power plant, water treatment plant, etc. which often use electric motors, if something abnormal is detected by monitoring a device state of the electric motor, a generator or a transformer installed in the plant, it is important in terms of reliability of the plant and enhancing operating ratio to obtain details of this abnormality.
An introduction of a state-of-device remote monitor system for observing various items of data obtained from a target device installed in the plant and monitoring a state of the device on the basis of these items of data, has been promoted over the recent years for attaining the above purpose.
Further, this type of state-of-device remote monitor system that targets not only the mechanical and electrical equipment, such as electric motors, generators, pumps, valves, and pipes, but also measuring devices for a calculator and a substrate, has been accelerated in its development and is at a stage of being introduced. The state-of-device remote monitor system, as compared with the conventional method in which an operator patrols inside the plant and observes the devices, is classified based on its usage into a system that measures the data of a target device periodically or arbitrarily and observes the state of the device when measured, and a system that measures the state of the target device on-line at all times and continuously monitors its state.
Moreover, the state-of-device remote monitor system takes a man-based method of manually extracting and inputting the data obtained from the various detectors to a database and manually analyzing the data accumulated in the database.
The state-of-device remote monitor system described above might, however, be operated by a method of monitoring the device state online at all times. In such a case, it is not realistic that the man-based process is done as an intermediary process between a data measurement by the detector and a judgment for presuming the device state on the basis of the measured data.
For example, Japanese Patent Application Laid-open No. Hei 7-209035 (titled State-of-Device Remote Monitor System) discloses, as a technology for obviating these problems, a conventional state-of-device remote monitor system in which the data extraction and analysis are automated. FIG. 27 shows a typical architecture of this system.
Referring to FIG. 27, a laser-based detector 22 such as a vibration system sensors, a temperature sensor and a visible image extraction sensor installed in an on-the-spot area 11 like a plant, detects a state of equipment device 21 such as an electric motor, a pump, a valve and a pipe. The detection signals thereof are transmitted to a maintenance tool 50 in a management area 12 existing at a remote distance via a dedicated transmission line 101. In the management area 12, the maintenance tool 50 receives the various items of data transmitted from the detector 22, and the received data are analyzed by a preset diagnostic/analytic program 52. A result thereof is displayed on a display unit 54.
The conventional state-of-device remote monitor system is thus constructed. Therefore, the dedicated transmission line 101 that connects the detector 22 directly to the maintenance tool 50, however, if a multiplicity of monitor target devices 21 exist in the on-the-spot area 11, it is required that cables 101 as the dedicated transmission lines be extended for the respective detectors 22 attached to the devices 21.
Further, a digital multiplex data transmission system generally used for a monitor control unit in the on-the-spot area 11 can be applied. In this case also, however, the cable for at least the data transmission is required to be extended.
Thus, if the monitor of the state of the device 21 needs the extension of the cable, there arises a problem related to a cost for introducing the cable even if possible of extending the cable.
Moreover, the monitor target device 21 may be installed at a high place or on the underground within the plant or within a storage container in a nuclear power plant, wherein it is considered difficult to extend a new cable. Therefore, a problem is that the extension of the cable becomes an obstacle against the introduction.